"Identification of truly thermal springs is an indispensable aid in the assessment of a region's geothermal characteristics. Over the years numerous lists of thermal springs in Arizona have been compiled and we present yet another. Although the word thermal implies heat, there is considerable subjective or arbitrariness in its application. In geothermal work what is important is anomalous or unusual heat-something above a norm. A functional scheme has been devised that is useful in identifying those Arizona springs judged to be carrying anomalous heat. The method is readily applied to any new springs that may be encountered. The results of this updated version are shown in Table 1. Also, possible heat sources are briefly outlined in the text."